package com.hit.basmath.learn.others;

/**
 * 798. Smallest Rotation with Highest Score
 * <p>
 * Given an array A, we may rotate it by a non-negative integer K so that the array becomes A[K], A[K+1], A{K+2], ... A[A.length - 1], A[0], A[1], ..., A[K-1].  Afterward, any entries that are less than or equal to their index are worth 1 point.
 * <p>
 * For example, if we have [2, 4, 1, 3, 0], and we rotate by K = 2, it becomes [1, 3, 0, 2, 4].  This is worth 3 points because 1 > 0 [no points], 3 > 1 [no points], 0 <= 2 [one point], 2 <= 3 [one point], 4 <= 4 [one point].
 * <p>
 * Over all possible rotations, return the rotation index K that corresponds to the highest score we could receive.  If there are multiple answers, return the smallest such index K.
 * <p>
 * Example 1:
 * <p>
 * Input: [2, 3, 1, 4, 0]
 * Output: 3
 * Explanation:
 * Scores for each K are listed below:
 * K = 0,  A = [2,3,1,4,0],    score 2
 * K = 1,  A = [3,1,4,0,2],    score 3
 * K = 2,  A = [1,4,0,2,3],    score 3
 * K = 3,  A = [4,0,2,3,1],    score 4
 * K = 4,  A = [0,2,3,1,4],    score 3
 * So we should choose K = 3, which has the highest score.
 * <p>
 * Example 2:
 * <p>
 * Input: [1, 3, 0, 2, 4]
 * Output: 0
 * Explanation:  A will always have 3 points no matter how it shifts.
 * So we will choose the smallest K, which is 0.
 * <p>
 * Note:
 * <p>
 * A will have length at most 20000.
 * A[i] will be in the range [0, A.length].
 */
public class _798 {
    public int bestRotation(int[] A) {
        int n = A.length;
        int[] a = new int[n];  // to record interval start/end
        for (int i = 0; i < A.length; i++) {
            a[(i + 1) % n]++;             // interval start
            a[(i + 1 - A[i] + n) % n]--;  // interval end
        }
        int count = 0;
        int maxCount = -1;
        int res = 0;
        for (int i = 0; i < n; i++) {  // find most overlap interval
            count += a[i];
            if (count > maxCount) {
                res = i;
                maxCount = count;
            }
        }
        return res;
    }
}
